/*
    *
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.hadoop.hbase.client.example;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Connection;
  import org.apache.hadoop.hbase.client.ConnectionFactory;
  import org.apache.hadoop.hbase.client.Table;
  import org.apache.hadoop.hbase.client.coprocessor.Batch;
  import org.apache.hadoop.hbase.ipc.BlockingRpcCallback;
  import org.apache.hadoop.hbase.ipc.ServerRpcController;
  import org.apache.hadoop.hbase.protobuf.generated.RefreshHFilesProtos;
  
  import java.io.Closeable;
  import java.io.IOException;
  
  /**
   * This client class is for invoking the refresh HFile function deployed on the
   * Region Server side via the RefreshHFilesService.
   */
  public class RefreshHFilesClient implements Closeable {
    private static final Log LOG = LogFactory.getLog(RefreshHFilesClient.class);
    private final Connection connection;
  
    /**
     * Constructor with Conf object
     *
     * @param cfg
     */
    public RefreshHFilesClient(Configuration cfg) {
      try {
        this.connection = ConnectionFactory.createConnection(cfg);
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  
    @Override
    public void close() throws IOException {
      if (this.connection != null && !this.connection.isClosed()) {
        this.connection.close();
      }
    }
  
    public void refreshHFiles(final TableName tableName) throws Throwable {
      try (Table table = connection.getTable(tableName)) {
        refreshHFiles(table);
      }
    }
  
    public void refreshHFiles(final Table table) throws Throwable {
      final RefreshHFilesProtos.RefreshHFilesRequest request = RefreshHFilesProtos.RefreshHFilesRequest
                                                                 .getDefaultInstance();
      table.coprocessorService(RefreshHFilesProtos.RefreshHFilesService.class, HConstants.EMPTY_START_ROW,
                               HConstants.EMPTY_END_ROW,
                               new Batch.Call<RefreshHFilesProtos.RefreshHFilesService,
                                               RefreshHFilesProtos.RefreshHFilesResponse>() {
                                 @Override
                                 public RefreshHFilesProtos.RefreshHFilesResponse call(
                                   RefreshHFilesProtos.RefreshHFilesService refreshHFilesService)
                                   throws IOException {
                                   ServerRpcController controller = new ServerRpcController();
                                   BlockingRpcCallback<RefreshHFilesProtos.RefreshHFilesResponse> rpcCallback =
                                     new BlockingRpcCallback<>();
                                   refreshHFilesService.refreshHFiles(controller, request, rpcCallback);
                                   if (controller.failedOnException()) {
                                     throw controller.getFailedOn();
                                   }
                                   return rpcCallback.get();
                                 }
                               });
      LOG.debug("Done refreshing HFiles");
    }
  }